I used points graphic (geoR) in this way: points(zn,pt.divide=c("quintiles"), main="Location map of Zn",lambda=1,col="gray",yl="coord y",xl="coord x",x.leg=0. 3, y.leg=5.5,dig.leg=2,cex.min=0.5,cex.max=1,) Can I reduce legend characters (a sort of cex)?